Methods of identifying genes conferring ethanol tolerance in yeasts, genes that confer ethanol tolerance, and mutant strains used to identify such genes are described. A gene herein designated HpETT1 was isolated from the yeast Hansenula polymorpha. Expression of HpETT1 in an ethanol sensitive mutant H. polymorpha strain designated 7E complimented ethanol sensitivity of the mutant. When multiple copies of the HpETT1 were integrated into the genome and overexpressed, the transformed strain demonstrated approximately 10-fold greater resistance to ethanol and resistance to the protein misfolding agent AZC. Expression of HpETT1 also increased ethanol tolerance in Saccharomyces cerevisiae. HpEtt1 has 39% sequence identity to a previously identified protein from S. cerevisiae denoted MPE1, however, the MPE1 gene does not confer ethanol resistance to the 7E mutant. Another gene from the yeast Pichia stipites was identified that encodes an orthologue protein having 37% identity to HpETT1 herein designated PsETT1 and also confers ethanol resistance to the 7E mutant.

Methods, compositions, and kits are provided for imaging a polypeptide of interest. Methods, compositions, and kits are also provided for site-specific transcriptional regulation of one or more genetic elements.

Methods, compositions, and kits are provided for imaging a polypeptide of interest. Methods, compositions, and kits are also provided for site-specific transcriptional regulation of one or more genetic elements.

The present disclosure provides, inter alia, compositions and methods for modulating and/or utilizing nucleocytoplasmic alpha-mannosyltransferase enzyme activity in yeast, e.g., to modulate the performance of the yeast in fermentation, respiration, bioproduction and/or bioprocessing. The disclosure also provides, inter alia, modified eukaryotic organisms comprising modulated nucleocytoplasmic alpha-mannosyltransferase enzyme activity, and uses of such modified eukaryotic organisms.

The present disclosure provides, inter alia, compositions and methods for modulating and/or utilizing nucleocytoplasmic alpha-mannosyltransferase enzyme activity in yeast, e.g., to modulate the performance of the yeast in fermentation, respiration, bioproduction and/or bioprocessing. The disclosure also provides, inter alia, modified eukaryotic organisms comprising modulated nucleocytoplasmic alpha-mannosyltransferase enzyme activity, and uses of such modified eukaryotic organisms.

Vaccine compositions including a yeast comprising an immunostimulatory polypeptide and optionally an antigenic polypeptide are provided herein. The immunostimulatory polypeptide and the antigenic polypeptide are expressed or displayed on the surface of the yeast vaccine composition. Methods of using the vaccine composition to vaccinate subjects are also provided.

Vaccine compositions including a yeast comprising an immunostimulatory polypeptide and optionally an antigenic polypeptide are provided herein. The immunostimulatory polypeptide and the antigenic polypeptide are expressed or displayed on the surface of the yeast vaccine composition. Methods of using the vaccine composition to vaccinate subjects are also provided.

Novel promoters which are derived from P. pastoris pastoris which are inducible or repressible under specific growth conditions are provided. These promoters are useful for regulating the expression of a desired structural gene, e.g., a mammalian polypeptide. Particularly preferred is the use of these novel promoters to regulate gene expression in polyploidal yeast such as diploidal P. pastoris produced by mating or spheroplast fusion.

Novel promoters which are derived from P. pastoris pastoris which are inducible or repressible under specific growth conditions are provided. These promoters are useful for regulating the expression of a desired structural gene, e.g., a mammalian polypeptide. Particularly preferred is the use of these novel promoters to regulate gene expression in polyploidal yeast such as diploidal P. pastoris produced by mating or spheroplast fusion.

Provided is an acid-resistant yeast cell that is genetically engineered to enhance activity of a radiation sensitivity complementing kinase, and a method of producing lactate by using the yeast cell.